PoE Splitter not putting out enough power?

[cgcmgr 0]

Hopefully one of you guys who use a PoE Splitter can answer this question.

 

My current setup is as follows: 1 Cat-6 cable with power and data over 2 sets of pins (1,2,3 & 6) and just power over the other 2 sets of pins (4,5,7,& . Power is being fed by 2 separate PoE Injectors for each 2 sets of pins. On the other end, I have 2 PoE splitters for each 2 sets of pins to power my camera, heater/blower and IR unit. The power coming out of one PoE Splitter is split and goes to the camera and a fan in my enclosure (about 17W total). The power from the other PoE Splitter is split and goes to my IR unit and the heater in the enclosure.

 

During the summer everything worked fine. Now that the temp is in the 30's here, my IR just goes on and off continuously. Looking at the PoE Splitter that feeds the IR unit (as well as the heater) I can see the power light is blinking on and off as the IR unit is engaged. Once the sun comes up and the IR turns off, the light on the PoE Splitter no longer blinks.

 

Both PoE Splitters give out 12V 24W but say they can do 27W. The IR Unit/heater combo added up to 25W (15w + 10W). I figured this was the problem so I swapped out the IR unit for a camera with 72 Leds (just using the camera for the IR, not for any video) and that is rated at 9W. So, 10W+9W is 19W, but it still blinks on and off.

 

The cable run is about 300', so I'm guessing there is a drop in voltage and wattage output. The PoE Injectors I'm using are rated at 56V, so I wouldn't think voltage drop would have been that much due to cable length. Regardless something is happening. Do you think there just isn't enough power being put out by the PoE Splitter to power both the heater and the IR Unit? I plan on running another cable in the spring just for the IR unit on it's own, hopefully that will solve the problem.

Chris

[hardwired 0]

Your voltage drops are probably excessive. Your best bet is to use a single 802.3at high power injector/splitter pair that utilizes all four pairs in the Ethernet cable, something like the PowerDsine unit here, http://www2.microsemi.com/PowerDsine/Documentation/Datasheets/PoE_951_Splitters.pdf, with the appropriate 802.3at injector,

http://www2.microsemi.com/PowerDsine/Products/Midspan/PD_9501G.asp

 

That setup is rated at a 54 Watt output, about the current limits for PoE technology.

[vector18 1]

I'm in Forest Hills, your neighbor. When did we hit the 30's? LOL

[cgcmgr 0]

@hardwired

If I did that, then I'd just be using the 1 PoE splitter and I would have to split the power coming out 4 times to run what I need, but I guess that is still better than what I currently have. Will all the splits degrade the power as opposed to 2 splits per 24W PoE Splitter?

 

@Vector18,

My cameras are located in Lockwood, NY- about 4 hours west from us where I am currently. Here the weather has been in the low 30's the last few days. How's the gas situation there? I'm heading back to Flushing on Monday and I'm hearing horror stories.

[hardwired 0]

Splitting the single source shouldn't be a problem. You may also want to evaluate whether you really need a heater, even though you are in a fairly cold environment. IP cameras tend to generate quite a bit of heat on their own.

 

I have relatives in White Plains and Princeton who are still without power, and a lot of roads blocked by trees and power lines down, it's still pretty ugly, from what I hear.

[vector18 1]

I haven't been able to get gas since last Wednesday. My work truck has 1/4 tank, my personal car has 1/4 tank, my personal truck has 1/4 tank, my bike has a full tank but too cold to ride. The news says the trucks are out for delivery but I haven't seen anything or heard of any stations selling gas. Anyway, I'm hoping I can get some on Sunday. I have to upgrade an old PC dvr with an 8 channel dahua analog and the job is about 20 minutes away. If my profit wasn't as high as it was, I would have cancelled the job.

As far as POE switches, I took a pakedge seminar and they seem to be good switches with good POE power.

[Kawboy12R 0]

Try plugging your numbers into this PoE calculator and see what it says. http://www.active-vision.com/CAT5-Voltage-Loss-Calculator-s/160.htm

[hardwired 0]

Try plugging your numbers into this PoE calculator and see what it says. http://www.active-vision.com/CAT5-Voltage-Loss-Calculator-s/160.htm

The current drop calculations there may not be completely useful, because the PoE setup uses DC-DC converters to change the 48-60 Volt applied on the cable to the 12 Volt needed for the devices, and without knowing the dropout voltage of the PoE splitter at the far end (and the efficiency of the conversion), you can't know exactly what the maximum you will be able to draw before the splitter shuts down.